I have 13 double KOs new this year and wonder what winter prep should I do for them? This forum is such a help to me. Thanks for all your advice.
Since Double Knock Out is hardy to Zone 4, you shouldn't need to do any winter prep. If you are worried, maybe pile up some leaves around the base. I would think that would be more than enough.
I agree with Kate. Although advertised as very hardy, mine experiences dieback and I have to prune it back quite a bit each spring. My only concern is to protect the crown and oak leaves do that well.
After spring pruning, it recovers quickly